Internal combustion engine



March 23, 1943. E. o. P. THEGE INTERNAL COMBUSTION ENGINE 5 Sheets-Sheet 2 Filed Feb. 2l, 1941 March 23, 1943.

r-:. o. P. THEGE 2,314,670

INTERNAL COMBUSTION ENGINE Filed Fb. 21, 1941 5 sheets-sheet s 5 Sheets-Sheet\ 4 y y E. o. P. THEGE INTERNAL COMBUSTION ENGINE Filed Feb. 21, 1941 March 23, 1943.

E. O. P. THEGE INTERNAL 'COMBUSTION ENGINE March 23, 1943.

` 5 Sheets-Sheet 5 Filed Feb. 21, 1941 Patented Mar. 23, 1943 2,314,670 INTERNAL COMBUSTION ENGINE Edvin Ossian Parcival Thege, Stockholm, Sweden, assigner to Aktiebolaget Atlas Diesel, Stockholm, Sweden Application February 21, 1941, 'Serial No. 379,947 In Sweden March 21, 1940 14 Claims.

The present invention relates to internal combustion engines of the type in which the piston is directed downwardly with respect to the crank shaft, for instance vertically mounted doublepiston engines, in which the two pistons work in opposite directions in the same cylinder, 4the upper piston of which is located as stated above.

In engines of the type hitherto known there is a drawback due to the fact that the lubricating oil in the crank casing located above the piston cannot be effectively prevented from entering into the engine cylinder.

In hitherto known constructions, it is true, separate scrape rings have been used, but this has not prevented the oil in the crank casing,

Y particularly when the engine is at rest, from running down into the cylinder and the piston, the rings having not been able to prevent entering of oil between the piston and the cylinder bore. This has caused too a rich lubrication of the piston and a formation of coke and an increased oil consumption caused thereby. It has also been well known that the consumption of lubricating oil in such engines is considerably greater than what can be considered economical and suitable from the point of View of a safe running.

The present invention has for its object to avoid the said drawback and consists essentially in means operative to prevent lubricating oil from reaching the piston rings on the piston to any considerable degree. kr

In the annexed drawings some embodiments of the invention are shown as applied to a vertically mounted two-stroke internal combustion engine having a double-piston arrangement of the class mentioned.

In the drawings, Fig. 1 is a vertical axial section of part of an engine according to one embodiment, and Fig. 2 is a vertical section along the line 2-2 in Fig. 1. Fig. 3 is sectional view of the piston according to a modification with appertaining parts of the cylinder. Fig. 4 is a sectional detail View of the cylinder and the upper piston according to a further embodiment. Fig. 5 is a sectional View of an engine according to further modification. Figs. 6 and 7 are sectional views similar to those shown in Fig. 1

The upper crank casing is denoted by 5 and .the lower one by 6. Mounted-in the said casings are the crank shafts 1 and 8, respectively, and the cranks are connected: to the pistons 3 and 4 by means of connecting rods 9 and Il), respectively, in the usual manner. The crank shafts are co-driven by means of a series of cylindrical gear wheels -to |5 mounted in the engine frame, and the power is taken out at the lower shaft 8. The scavenging air receivers are denoted by |6 and the exhaust pipes by The fuel injection into the chamber I8 between the pistons takes place at |9.

In the embodiment shown in Figs. 1 and 2, the piston motions are made equal. Besides, with respect to the length of stroke and the diameter and length of the pistons the said motions are so made that the pistons, also in their inner end positions, project outside the cylinder 5 are outlets 23 for lubricating oil collected in the casing, and from said outlets the oil is drawn off through pipes 24 to the lower crank casing E. Oil outlets 25 are provided in the cylinder wall also at the packing-box 20, 2|, which outlets maybe connected to the pipes 24 by means of pipes 26.

By the fact that according to the invention the piston 3 always, even in its lower end position (that one shown in the figures), projects above the upper end of the cylinder, or, as in the embodiment shown, above the packing-box ring 2|, the oil in the crank casing 5 is prevented from running down into the cylinder. This favorable action is assisted by the packingbox 2|), 2| and also the annular ridge 22, which serves as a guide for the oil towards the outlets 23. The oil, which possibly enters into the packing-box, is drawn off through the outlets 25 and the pipes 26. Even if during stoppage of the engine the piston 3 would be wholly lled with oil, there is no risk of the oilentering into the cylinder, inasmuch as, as during running. the oil will be conducted towards the outlets.

In order that,` in an arrangement according to the embodiment above described, the piston shall not obtain too great a length and, thus, too great a weight and in vorder to maintain reasonable height dimensions (distance between the shafts) the leng-th of stroke must be made relatively short. Thus, by making the lower piston motion equal tothe upper one, an engine is obtained, which permits of a very high number of revolutions, without thereby causing too high a speed of the pistons. Thus, an engine is obtained, which asv to the weight and size is smaller than what can be obtained for the same power in an engine having a greater length of stroke. A further advantage is that the transmission of motion or the interconnecting of the two crank shafts will be facilitated, since, due

to the construction shown, the distance betweenthe shafts will be reduced.

Besides, in the embodiment shown, the pistons are made equal (with the same length), whereby a balancing will be obtained. As mentioned, a packing-box is provided also at the lower end of the cylinder.

In order further to prevent the oil from running down into the cylinder the piston 3 may be provided with an annular drip nose 21, which conducts the oil outwardly towards the outlets 23, as apparent from the embodiment shown in Fig. 3.

A further safeguard against the running down of oil can be obtained by providing a packingbox also at a lower place in the cylinder. Such an embodiment is shown in Fig. 4. Here, a separate guide cylinder 28 is inserted into the working cylinder, the packing-box rings 20 resting against the upper end surface ofsaid guide cylinder. whereas two further packing-rings 29 are placed at the lower or inner end of said cylinder, which latter rings may be of the same sort as are the upper rings 20 and rest against the bottom of the turned out recess in the working cylinder, in which the guide cylinder is inserted. The space of the lower packing-box is provided with an outlet 30 for oil collected at that place. This packing-box must be so located that the uppermost piston ring 3| does not reach the packing-box in the uppermost position of the piston. The upper packing-box 20, 2| may be dispensed with, if desired.

The embodiment according to Fig. differs from the one shown in Figs. 1 and 2 substantially only in the respect that the two piston motions are made different. Thus, the lower piston motion has a longer stroke than has the upper one. Here, the lower stroke is twice as great as the upper one. Such a construction advantageously can be used in large engines, such as marineengines or stationary engines. By such an arrangement the advantage is gained that the upper crank casing with the enclosed shaft and piston motions can be loosened from the lower part and lifted in a relatively easy manner, and then both pistons will be easily accessible for inspection and further dismounting, if required.

The engine shown in Figs. 6, 7 and 8, as to its general construction, is similar to that of Figs. 1 and 2 and Fig. 4, and similar details are denoted by the same reference numerals.

Inserted in a turned out recess in the upper part of the working cylinder 2 is a guide cylinder 28, packing rings 29, for instance of the sort described above, being placed between the lower end of said guide cylinder and the bottom of said recess. similar to the embodiment shown in Fig. 4. Made in the guide cylinder above said rings is an annular recess 33, which wholly independently of the position of the piston 3 is in permanent commuryication with the upper crank chamber through vertical channels 32 made in the guide cylinder. Also, the recess 33 has an outlet 34 for the lubricating oil, which through a pipe 35 may be conducted to the lower crank casing 6. Made lat two diametrically opposed sides at the upper end of the piston 3 are recesses 36, through which, in the inner end position of the piston, the interior of the hollow piston obtains a communication with the annular recess 33 in the guide cylinder, so that, in the said position of the piston, a drawing oif. of lubricating oil can take place from the said piston chamber. However, if desired, the piston may be so made that its upper edge in the inner end position of the piston wholly or partly uncovers the annular recess 33, so that drawing off of oil from the interior ofthe piston can take place. However, the oil in the piston always has a chance to escape through the channels 32, even if the recess 33 be wholly covered by the piston.

As in the embodiment according to Figs. 1 and 2, outlets 23 for lubricating oil collected in the upper crank casing 5 are provided at the lower part of said casing, pipes 24 being connected to said outlets to conduct the oil to the lower crank casing 6. An outlet 30 is provided also at the packing-box 29, which may be connected to the pipe 23 by means of a pipe 31.

According to the invention a channel arrangement 32, 33, 34 having a freeoutlet is provided in the cylinder in permanent communication with the upper crank casing, and thus the oil in the said casing will be prevented from running down into the cylinder to any considerable degree. In this action the packing-box 29 also assists, and, besides, oil which possibly enters into the packing-box will also be drawn off. Even if during stoppage of the engine the piston 3 would be wholly filled with oil, there is no risk of the oil entering into the cylinder, in as much as the same either through the recess 36 in the piston ory by suitable construction of the latter or simply through the channels 32 will be conducted to the annular recess 33 and to the outlet 34.

Evidently the said recess 33 needs not have the shape of an annular channel, but may be replaced by one or more pockets in the cylinder wall having communication with the crank chamber and also with the outlet.

What I claim as new and desire to secure by Letters Patent of the United States of America 1. An internal combustion engine, comprising a substantially .vertically mounted cylinder, a trunk piston movable in said cylinder, piston rings on said piston, a crank casing at the top of the cylinder, a crank shaft mounted in said crank casing and in operative connection withv said piston, the overflow from said piston being in permanent communication with an outlet in all positions of the piston.

2. An internal combustion engine, comprising a substantially vertically mounted cylinder, a trunk piston movable in said cylinder, piston rings at the lower part of said piston, a crank casing at the top of said cylinder, and a crank shaft mounted in said crank casing and in operative connection with said piston, the piston motion being so made with respect to the length of stroke and the diameter and the length of the piston that the latter always, even in its lower end position, projects above the cylinder and has its overflow in permanent communication with an outlet.

3. An internal combustion engine, comprising a substantially vertically mounted cylinder, a

8. An internal combustion engine, comprising` trunk piston movable in said cylinder, piston rings at the lower'part of said piston, a crank casing at thetop of said cylinder, a crank shaft mounted in said crank casing'and in operative connectionwith said piston, and a packing-box at the upper end of said cylinder, the piston motion being so made with respect to the length of stroke and the diameter and the length of the piston that the latter always, even in its. lower end position projects above the cylinder and has its overflow in permanent communication with an outlet.

4. An internal combustion engine, comprising a substantially vertically mountedY cylinder. a trunk piston movable in said cylinder, piston rings at the lower part of said piston, a crank casing at the top of said cylinder, a crank shaft mounted in said crank casing and in operative connection with said piston, and a packing-box in the cylinder at a place below the upper end thereof, the piston motion being so made with respect to the length of stroke and the diameter and the length of the piston that the latter always, even in its lower end position, projects above the cylinder and has its overflow in permanent communication with an outlet.

5. An internal combustion engine, comprising a substantially vertically mounted cylinder, a trunk piston movable in said cylinder, piston rings at the lower part of said piston, a crank casing at the top of said cylinder, a crank shaft mounted in said crank casing and in operative connection with said piston, a packing-box 'at the upper end of said cylinder, and a packingbox in the cylinder at a place below the upper end thereof, the piston motion being so made with respect to the length of stroke and the diameter and the length of the piston that the latter always, .even in its lower end' position, project above the cylinder and has its overflow in permanent communication with an outlet.

6. An internal combustion engine, comprising a substantially vertically mounted cylinder, a trunk piston movable in said cylinder, piston rings at the lower part of said piston, an annular drip-nose at the upper end of said piston, a crank casing at the top of said cylinder, and a crank shaft mounted in said crank casing and in operative connection with said piston, the piston motion being so made with lrespect to the length of stroke and the diameter and the length of the piston that the latter always, even in its lower end position, projects above the cylinder and has its overflow in permanent communica-l tion with an outlet.

7. An internal combustion engine, comprising a substantially vertically mounted cylinder, two trunk pistons movable in opposite directions in said cylinder, piston rings at the inner parts of said pistons, an upper crank casing at the top of said cylinder, a crank shaft mounted in said upper crank casing and in operative connection with the upper one of said pistons, a lower crank casing at the bottom of said cylinder, a crank shaft mounted in said lower crank casing and ir. operative connection with the lower one of said pistons, and power transmission means between said crank shafts, the piston motion of at least the upper one of said pistons beingr so made with respect to the length of stroke and the diameter and the length of the piston that the latter always, even in its inner end position, projectsabove the cylinder and has its overflow in permanent communication with an outlet.

' with the upper one of said pistons, a lower crank iii Vcasing at the bottom of said cylinder, a crank shaft mounted in said lower crank casing and in operative connection with the lower one of said pistons, and power transmission means between said crank shafts, the piston motion of at least the upper one of said pistons being so made with respect to the length of stroke and the diameter and the length of the piston that the latter always, even in its inner end position, projects above the cylinder and'has its overflow in the permanent communication with an outlet,both of said pistons having similar piston motions.

9. An internal combustion engine, comprising a substantially vertically mounted cylinder', two trunk pistons movable in opposite directions in said cylinder, piston rings at the inner parts of said pistons, an upper crank casing at the top of said cylinder, a crank shaft mounted in said upper crank casing and in operative connection with the upper one of said-pistons, a lower crank casing at the bottom of said cylinder, a crank shaft mounted in said lower crank casing and in operative connection with the lower one of said pistons, and power transmission means between said crank shafts, the piston motion of at least the upper one of said pistons being so made with respect to the length of stroke and the diameter and the length of the piston that the latter always, even in its inner end position, projects above the cylinder and has its overflow in the permanent communication with an outlet. the piston motion of said lower piston having a greater length of stroke than has the upper one.

10. An internal combustion engine, comprising a substantially vertically mounted cylinder, a

' trunk piston movable in said cylinder, piston rings at the lower part of said piston, a crank casing at the top of said cylinder, a crank shaft mounted in said crank casing and in operative connection with said piston, an outlet in the wall of said cylinder, and a channel arrangement in the said wall forming a permanent communication between the said crank casing and said outlet.

l1. An internal combustion engine, comprising a substantially vertically mounted cylinder, a

trunk piston movable in said cylinder, piston rings at the lower part of said piston", a crank casing at the top of said cylinder, a crank shaft mounted in said crank casing and in operative connection with said piston, an outlet inthe Wall of said cylinder, and a channel arrangement in the said wall forming a permanent communication between the said crank casingr and said outlet. said channel arrangement comprising an annular recess in the said wall in communication with said outlet and at least one channel in said wall forming a communication between said crank casing and said annular recess.

12. An internal combustion engine. comprising a substantially vertically mounted cylinder. a trunk piston movable in said cylinder` piston rings at the lower part of said piston, a crank casing at the top of said cylinder, a crank shaft mounted in said crank 'casing and in operative connection with said piston, an annular recess having an outlet in the wall of said cylinder, at least one channel in'the said wall forming a communication between said crank casing and .said recess, and a packing-box in the cylinder at a place below said annular recess.

13. An internal combustion engine, comprising a substantially vertically mounted cylinder, a trunk piston movable'in said cylinder, piston rings at the lower part of said piston, a crank casing at the top of said cylinder, a crank shaft mounted in said crank casing and in operative connection with said piston, an outlet in the wall of said cylinder, and a channel arrangement in the said wall forming a permanent communication between the said crank casing and said outlet. said channel arrangement comprising an annular recess in the said wall in communication with said outlet and at least one channel in said wall forming a communication between said crank casing and said annular recess, the piston being so made as to cover said annular recess at its inner end position and being further recessed at its upper edge at least at one place to form a communication between said annular recess and the interior of the piston.

14. An internal combustion engine, comprising a substantially vertically mounted cylinder, a trunk piston movable in said cylinder, piston rings at the lower part of said piston, a crank casing at the top of said cylinder, a crank shaft mounted in said crank casing and in operative connection with said piston, an outlet in the wall of said cylinder, and a channel arrangement in the said walllforming a permanent communication between the said crank casing and said outlet, said channel arrangement comprising an annular recess in the said wall in communication with said outlet and at least one channel in said wall forming a communication between said crank casing and said annular recess, the piston being so made as to uncover at least part of the said annular recess in its inner end p0- sition.

` EDVIN OSSIAN PARCIVAL TI-IEGE. 

